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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32728 results found.

  1. EP260101a: Global MASTER-Net observations report
  2. GRB 260102A: LCO optical upper limits
  3. GRB 260102A: Swift-XRT observations
  4. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  5. GRB 251230A / EP251230a: GECAM-B detection
  6. GRB 260102A: SVOM/VT optical counterpart
  7. GRB 251230A / EP251230a: Insight-HXMT/HE detection
  8. GRB 260102A: Swift ToO observations
  9. GRB 260101A: Fermi GBM Observation
  10. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  11. GRB 260101A: GECAM-B detection
  12. GRB 260101A: NOT spectroscopic observations
  13. GRB 260101A: SVOM/GRM observation
  14. Swift GRB 260101A: Global MASTER-Net observations report
  15. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  16. GRB 260101A: LCO detection of the optical counterpart
  17. GRB 251230A / EP251230a: SVOM/VT optical continued observations and upper limit
  18. GRB 251230A: GRANDMA/TAROT Early Detection
  19. GRB 251230A / EP251230a: further NOT optical observations revealing shallower decay or possible rebrightening
  20. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  21. EP251229a: Optical upper limit with Kinder observations
  22. GRB 251230A: 1.3m DFOT optical upper limit
  23. GRB 251222A: Mondy Optical Observations
  24. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  25. GRB 251230A: Swift/UVOT detection
  26. GRB251230A: 7DT optical upper limits
  27. GRB 251230A / EP251230a: NOT observations and spectroscopic redshift upper limit z < 2.2
  28. EP251229a: BOOTES-2 early optical upper limit
  29. GRB 251230A: GOTO optical upper limit
  30. EP251229a: NOT optical upper limits
  31. GRB 251230A / EP251230a: SVOM/VT optical observation
  32. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  33. GRB 251230A: Early optical counterpart detection by LCO.
  34. EP-WXT trigger 01709250662 Mephisto and 50cm telescope follow-up
  35. GRB 251230A: Optical Observations via Virtual Telescope Project, Italy
  36. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  37. GRB 251230A/EP#01709250693 (likely EP251230a): FTW optical and NIR observations
  38. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  39. Swift GRB 251230A: Global MASTER-Net observations report
  40. The EP-WXT trigger 01709250693/GRB 251230A: Las Cumbres detection of the optical counterpart
  41. EP251229a: Global MASTER-Net observations report
  42. GRB 251226A: Glowbug gamma-ray detection
  43. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  44. GRB 251129A: redshift correction and SN detection at z = 0.505 with GTC
  45. Fermi GRB 251228A: Global MASTER-Net observations report
  46. GRB 251226A: SVOM/GRM observation
  47. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  48. GRB 251222A: NUTTelA-TAO Early Measurements
  49. GRB 251222A/EP251222b: Optical detection with Kinder observations
  50. EP251222a: Optical upper limit with Kinder observations
  51. GRB 251221A: Swift-BAT refined analysis
  52. GRB 251222A/EP251222b: FTW optical and NIR observations
  53. EP251222a: FTW optical and NIR observations
  54. GRB 251205A: Kilonova-Catcher optical afterglow detection
  55. GRB 251222A: AbAO optical observations
  56. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  57. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  58. EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
  59. GRB 251222A: ZTSH BVRI optical observations
  60. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  61. GRB 251222A: Continued 1.3m DFOT optical observation
  62. EP251220a: 3.6m DOT optical afterglow detection
  63. GRB 251222A: Fermi GBM Observation
  64. EP251220a: CrAO ZTSh optical observations
  65. EP251221a: PRIME upper limit
  66. EP251222a: Global MASTER-Net observations report
  67. GRB 251222A / EP251222b: GECAM-B observation
  68. EP251221a: Liverpool Telescope upper limits
  69. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  70. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  71. Konus-Wind detection of GRB 251222A / EP251222b
  72. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  73. EP251222a: NTT/ULTRACAM optical observations
  74. EP251222a: GOTO optical upper limit
  75. GRB 251222A / EP251222b: GOTO optical counterpart detection
  76. GRB 251222A / EP251222b: LCO optical observations
  77. GRB 251222A: 1.3m DFOT optical detection
  78. GRB251221A: 7DT optical upper limits
  79. EP251222a: GSP Optical Counterpart Detection
  80. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  81. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  82. EP251222b/GRB 251222A: SVOM/GRM observation
  83. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  84. EP251221a: Global MASTER-Net observations report
  85. GRB 251222A: PRIME near-infrared detection
  86. EP251221a: NOT optical upper limit
  87. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  88. GRB 251222A: NOT optical observations
  89. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  90. IPN triangulation of GRB 251220B (short)
  91. GRB 251222A: Swift ToO observations
  92. GRB 251222A: SVOM/VT optical candidate
  93. GRB 251222A: SVOM detection of a long burst
  94. EP251220a: PRIME upper limit
  95. EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
  96. GRB 251221A: PRIME near-infrared observation
  97. EP251220a: NOT optical observations
  98. EP251220a: FTW optical and NIR observations
  99. GRB 251221A: UAFO and Mondy optical upper limit
  100. GRB 251221A: Swift/UVOT Upper Limits

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